Dear lammps users:
i have tested a simulation run of a solid ZnO system using Reaxc package.
my simulation box contain 384 atoms with 11x12x16A° dimension.
the steps number to run is 44000 on 1 process with brendsen temp control.
the first run at T = 100 °K was succefully finished.
when i change the temperature to 200 or 300 °K the run stop and the next message appear:
ERROR: failed to allocate 287623448 bytes for array list: tree_bodiesapplication called MPI_Abrot<MPI_COMM_WORLD, -14> - process 0
i know form the lammps manual as well as from the mail-list that this prorblem means that there is no sufficient memory to allocate. however i haven’t understand why for 100 °K this problem don’t appear and appear only for high temperaute.
and what the solution.
A common reason for this behaviour is that higher temperature means higher disorder in your system, which leads to slightly larger local density somewhere. This in turn might trigger an increase in the neighbor list size. You might also have a unphyiscal (i.e. far from equilibrium) system where again some significant increase in the local density is triggered by a higher temperature. While the first is something which increases memory comsumption only slightly (so you only have a problem if you are using most of the main memory of your machine in the first place) the latter can lead to significantly more memory usage.
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Well, 2 Gb is a huge allocation. You can ask the
package author why that is occurring. My guess is
you have a bogus system. E.g. bad input.